One of the important factors to make a balance between number of grazing livestock and grazing capacity is whether forage contains sufficient energy and protein during grazing period or not. Therefore in this study, forage quality was evaluated for important species in steppe rangelands of Changuleh located in Ilam province. To do this, samples from four species of Hammada salicornia, Salsola lanchnantha, Convolvulus oxyphyllus and Pteropyrum noeanum, those made considerable components of rangelands vegetation in the region, were collected during three phenological stages (active growth, flowering and maturating) over 2008. Then chemical compositions were determined including crude protein (CP), acid detergent fiber (ADF), dray matter digestibility (DMD) and metabolizable energy (ME). According to the results, maximum CP was obtained from Hammada salicornia in active growth stage. Crude protein component of this species was more than critical level (7%) for sheep in the maintenance condition. Also in this species, ME was in higher critical level (8 Mj/kg) compared with the other species